REPRIMANDED. Alfonse D'Amato, 54, Republican U.S. Senator from New York; for acting "in an improper and inappropriate manner" by allowing his brother to use his office on behalf of the Long Island, N.Y., division of Unisys, a defense contractor; by the Senate Select Committee on Ethics; in Washington. After a 19-month inquiry, the committee announced that it had found no evidence that D'Amato acted illegally on behalf of Unisys in exchange for campaign contributions. It did not recommend any punishment by the full Senate. But, in issuing the harsh condemnation of a colleague, the committee faulted D'Amato for "failing to establish appropriate standards for the operation of his office."